Self-regulating arc-current generator



Sept. 18, 1923.

1,468,155 .1. A. HOLIFIELD SELF REGULATING ARC CURRENT GENERATOR Fil ed March 21. 1921 ATTORNEY Patented Sept. 18, 1923.

UNITED sTATES 1,468,155 PATENT OFFICE.

JOSEPH A. HOLII'IELD, OI MOBILE, ALABAMA, ASSIGNOR TO WRITE FUEL OIL EN- GINEEBING CORPORATION, OF NEWYORK, N. Y., A CORPORATION OF NEW YORK.

SELF-BEGULATING ABC-CURRENT GENERATOR.

Application filed March 21, 1921. Serial No. 154,277.

To all whom it may concern:

Be it known that I, JOSEPH A. HOLIFIEID,

a citizen of the United States of America.

- ance in the are so that a substantially constant current is maintained in the arc.

The chief object of my invention is to accomplish the ends aforesaid in the simplest and most inexpensive manner possible and by means which in its operation will not involve an appreciable loss of current in connection with its regulating functions.

I have conceived that an electric generator with a single work circuit commutator and twin independent parallel fields (o-operating with a single armature, one field being so excited as to maintain a substantially constant magnetic intensity, while the other field is variably excited responsive to variations in the resistance in the arc, will produce by the sum of the magnetic influence of its twin fields on. the armature a current of substantially constant characteristics in the arc.

As a modification of this idea and for the purpose ofenabling the use of a low er voltage generator, the set of fields in circuit with the arc can be compounded and differentially wound.

It is a further object of my invention to design the generator so as to be self exciting, thus enabling the same to be driven by any available sourcev of power and to this end the generator is provided with an exciting commutator and winding.

A further advantage of my invention lies in the fact that by reason of the effect of the difference of the magnetic intensity of the twin fields on a common armature winding at the same time, all sparking of the brushes is eliminated under all kinds of varying and sudden changes in the are.

In order that my invention in its preferred embodiment may more clearly uncurrent flow through the arc circuit of the derstood by those skilled in the art, reference is made to the accompanying drawings in which I have diagrammaticallyillustrated self-regulating generators em-. bodying the several features of my invention above set forth in their simplest form.

In. Fig. 1 I diagrammatically illustrate an arc current generator with twin independent parallel fields.

In Fig. 2 I illustrate diagrammatically the same type of generator with the fields in circuit with the are having compound differential windings.

In Fig.3 I show a generator similar to Fig. 2 with an exciting commutator and armature coil therefor, which makes it a self excited unit.

Similar reference numerals refer to similar parts throughout the drawings.

In the embodiment of my invention illustrated in Fig. 1, I show a shaft 1 driven by any suitable source of power and I mount thereon an armature 2. This armature is elongated to permit of its co-operation with twin parallel fields 3 and 4 which are independent of each other and which both exert a joint effect at the same time upon the same coil of the armature windings typically illustrated at 5. The armature core is preferably designed with a gap 6 between the independent sets of poles,

but this is only preferable construction and is not essential. Current from any direct current substantially constant potential source is supplied by a conductor7 to the field windings 3 surrounding the poles 8, the current returnin over a conductor 9 through a rheostat 10. he generator has any standard type of commutator 11 connected in any normal manner with the armature windings and having its brushes 12 connected in series with the are circuit 13 which includes electrodes 14 and 15 and also which includes, in series therewith, the field coils 4 surrounding the other set of poles 16. The twin parallel fields 8 and 4 are so wound as to produce opposite polarity and they should be sowound and proportioned as to allow a predetermined flow of current through the arc circuit 13.

In operation, with the arc circuit closed before striking the arc the independent fields approximatelyneutralize each other, the field 3 predominating and causing a the are substantially constant within the normal limits.

In the compound differentially connected generator design shown in Fig. 2, the parts are all as described in Fig. 1, except that I place the rheostat 10 in a branch from conductor 7 and by a branch circuit 17 from the same conductor I supply the constant potential D. C. current under control of a rheostat 18 to a differential winding 19 on the-poles 16, these windings connecting with the return conductor 9. This generator is of low voltage, the armature 2 being wound say for 25 volts as contrasted with a 50 volt winding for the armature in Fig. 1. In the operation of this type of machine, with the arcing electrode short circui'ted, the series winding 4 predominates over the differential winding 19, producing opposite polarity in the twin fields and as a result of their neutralizing influences, a low voltage current is produced in the arcing circuit. its the arc is drawn the series field windings 4 are weakened until they are substantially balanced by the winding 19 which occurs under working conditions when the arc has been drawn to its normal length, whereupon the welding current is enerated entirely by the magnetic strengt of the fields 3. As the arc is extended towards its maximum limit the shunt fields 19 predominate and change the polarity of the poles 16, whereupon both fields act jointly to increase the voltage in the welding circuit and this increase is throughout maintained automatically in direct proportion to the resistance in the arc.

In Fig. 3 I show an embodiment of my invention which is especially designed for any type of drive, which necessarily involves the designing of the generator so that it will be self exciting. In this design the windings of the twin fields are as described in connection with the low voltage generator (Fig. 2), but the field windings may be as in Fig. 1. In this arrangement the armature shaft 1 carries the supplemental exciting armature 20 having brushes 21 connected in the supply circuit 7, 9", corresponding to the circuit 7, 9, in Figs. 1

2. The commutator is connected to an armature winding, typically illustrated b the coil 22, which extends only under tile influence of the fields 3 which are of substantially constant magnetic intensit The magnetic intensity of the series fiel s 4 will naturally vary with the resistance in the are. By use of the special exciting winding 22 the generator becomes self exciting and constitutes a self contained welding unit which can be used at an point where any suitable power is availa 1c.

The sum of the strength f the twin fields upon the single armature winding or a winding that is common to the twin poles at the same time will in all designs var Y the armature voltage in proportion to t e resistance in the work circuit.

In the design shown in Fig. 2, if the pole 8 equals plus 25 and pole 16 equals minus20, the voltage at the brushes will be plus 5. When pole 8 equals plus 25 and pole 16 equals zero, the voltage would equal plus 25 volts, and when pole 8 equals plus 25 and pole 16 equals plus 20, the voltage would equal 45 volts. The voltage thus varies throughout the range from the difference to the sum of the magnetic intensity of the two poles. 7

Owing to the effect of the difference of the magnetic intensity of the twin fields on a common armature winding at the same.

time, all sparking of the brushes is eliminated under all kinds of varying and sudden changes in the arc.

The detailed construction or arrangement of parts can be widely varied without departure from the principle underlying my invention, which involves the utilization of independent fields to regulate by their joint control of the armature, with the regulating function taking place in the armature itself by causin a bucking current to regulate the flow 0 current in the arc.

Having thus described my invention. what I claiin as new and desire to secure by Letters Patent, is

1. A self-regulating electric current generator for a welding arc. comprising a single armature, a single commutator for the work circuit, twin fields adapted to exert their magnetic influence at different points upon the same coil of the armature winding at the same time, and means to vary the relative value of the field energizing currents to regulate the voltage of the generator in proportion to the resistance in the arc and maintain the current in the are substantially constant.

2. A self-regulating electric current generator for a welding arc. comprising a commutating means. a single armature for the work circuit, twin sets of poles disposed to exert their magnetic influence simultaneously on thesame coil of the armature winding, and field circuits for said sets of poles adapted to vary the sum of the magnetic indifferent circumferential zones of the armature, and an independent field circuit for each set of les, one of said field circuits being excite by a substantially constant potential current and the other by the welding current.

4. A self-regulating electric current generator for a welding are, comprising a commutator, an armature, a lurality of pole pieces disposed to exert t eir magnetic influence simultaneously on the same coil of the armature winding, a separate field circuit for each of said oles, and means to excite one field circuit a constant exciting current and the other by a variable exciting current responsive to variations in resistance in the arc.

I 5. A-self-regulating electric current generator for 'a welding arc, comprising a single commutator for the welding current, a single armature, two fields havin independent pole pieces of opposite polarity disposedto exert their magnetic influence jointly and simultaneousl same coil of 't e armature winding, means to excite one field to maintain its magnetic intensity s'ubstantially constant, and means to va the magnetic intensity of the other fiel responsive to the varying resistance in the arc.

6. A self-regulating dynamo for generating current for an electric are, com rising an armature, asingle commutator or the work circuit, means to maintain a field ofsubstantially constant magnetic intensity surrounding one end rtion of the armature, means to maintain a field of magnetic intensity surrounding vthe other end portion of said armature which varies with the resistance in the arc.

7. A low voltage self-regulating dynamo for generating current for an electric are,

com rising an armature, a sin 10 commutator or the work circuit, twin eldsfor said armature arranged lengthwise of the armature'to exert their in netic influence on different transverse sections thereof, one havinga substantially constant ma etic intensity and the other having. ifi'erential compound windings, the magnetic intensity on different parts .of the and the opposed magnetic intensity of the other being variable responsive to the resist ance in the arc, the sum of the magnetic intensity of the twin fields being proportionate to the said resistance in the arc.

8. A low voltage self-regulating d namo for generating current for an electric are, com rising an armature, a single commutator or the work circuit, twin fields for said armature arranged side by side lengthwise of the armature, one field having a single winding and the other having compound differential windings comprising a substantially constantly excited wlnding and an opposed variabl excited Winding, the varia tions in the atter being responsive to the varying resistance in the arc.

9. A self-regulating electric current genorator for an arc, comprising an armature, an exciting commutator and a work circuit commutator, twin fields adapted to exert their magneticinfiuence at the same time on different portions of the same armature winding, means to excite one vfield to pro: duce a substantially constant magnetic in tensity, means to excite the other field to produce a magnetic intensity which varies in direct proportion to the varying resistance in the arc, and anexciting winding in the armature exposed only to the magnetic influence of said constant field.

10. In a dynamo-electric machine the 1 a second set of pole-pieces, an armature cooperating therewith, said pole-pieces spanning substantially the same armature conductors, of an exciting winding and a series winding disposed upon said-respective sets of poleieces, said windings being wound differentially with respect to each other.

In testimony whereof I aflix my signature.

JOSEPH A. HOLIFIELD.

Witness:

Noam Wm. 

